Practical Evaluation of Low-Frequency Vibration Energy Harvesting for Creating Green RFID and IoT Devices

One of the main limitations for the development and deployment of many Green Radio Frequency Identification (RFID) and Internet of Things (IoT) systems is the access to energy sources. In this aspect batteries are the main option to be used in energy constrained scenarios, but their use is limited to certain cases, either because of the constraints imposed by a reduced-form factor, their limited lifespan, or the characteristics of the environment itself (e.g. operating temperature, risk of burning, need for fast response, sudden voltage variations). In this regard, supercapacitors present an interesting alternative for the previously mentioned type of environment, although, due to their short-term capacity, they must be combined with an alternative energy supply mechanism. Energy harvesting mechanisms, in conjunction with ultra-low-power electronics, supercapacitors and various methods to improve the efficiency of communications, have enabled the emergence of battery-less passive electronic devices such as sensors, actuators or transmitters. This paper presents a novel analysis of the performance of an energy harvesting system based on vibrations for Green RFID and IoT applications in the field of maritime transport. The results show that the proposed system allows for charging half of a 1.2 F supercapacitor in about 72 minutes, providing a stable current of around
$210 \mu A$
and a power output of 0.38 mW.